Automobile windshield wiper blade

ABSTRACT

An automobile windshield wiper blade ( 10 ) having an elongated belt-shaped, flexible resilient support element ( 12 ), on the lower belt surface ( 22 ) which faces the windshield and has an elastic rubber wiper strip ( 24 ) extending along the windshield parallel to the longitudinal axis. A wind deflection strip ( 42  or  112 ) on the upper belt surface ( 16 ) has an incident surface ( 54  or  140 ) facing the direction of driving wind (arrow  52 ). The deflection strip extends longitudinally, and has two sides ( 48, 50  or  136, 138 ) that diverge from a common base point ( 46  or  134 ) as seen in cross section, such that the incident surface ( 54  or  140 ) is located at one exterior side ( 50  or  138 ) and the wind deflection strip has a constant cross section along its entire length. The support element has outer edges, and the sides of the wind deflection strip have respective free ends that have respective claw-like extensions that grip the outer edges of the support element, wherein the wind deflection strip can be snapped or slid longitudinally onto the outer edges.

RELATED APPLICATION

This application is a continuation of co-pending U.S. application Ser.No. 12/364,092, filed Feb. 2, 2009, which is a divisional of U.S.application Ser. No. 11/760,394, filed Jun. 8, 2007, now U.S. Pat. No.7,484,264, which is a divisional of U.S. application Ser. No.10/312,279, filed Jul. 29, 2003, now U.S. Pat. No. 7,228,588, the entirecontents of all of which are hereby incorporated herein by reference.

BACKGROUND

In wiper blades with a spring-action support element, the supportelement is intended to guarantee as even a distribution of wiper bladepressure onto the windshield issued from the wiper arm as possible, andover the entire wipe field swept by the wiper blade. By appropriatelybending the un-loaded support element into shape—the unloaded statebeing when only the two ends of the wiper blade sit against thewindshield—the ends of the wiper strip, which sits completely againstthe windshield when the wiper blade is in operation, are pushed towardthe windshield by the loaded support element, even if the radii ofcurvature of spherically curved vehicle windshields change with thewiper blade position. The curvature of the wiper blade must therefore besomewhat greater than the maximum curvature measured within the wipefield on the windshield to be wiped. This is because during wiping, thewiper strip, or its wiping lip that sits against the windshield, must becontinuously pressed against the windshield with a specific force. Thesupport element thus replaces the expensive stirrup design with twoflexible rails located in the wiper strip, as is practiced inconventional wiper blades (DE-OS 15 05 257) since the support elementprovides the necessary cross-stiffening of the elastic rubber wiperstrip in addition to providing a distribution of pressure. Specifically,in the known wiper blade the contact force directed toward thewindshield that is exerted by a wiper arm onto a main stirrup isconveyed to two claw-like stirrups and distributed from these onto theelastic rubber wiper strip via four claws. The two flexible rails ofthis wiper blade mainly provide a cross-stiffening of the wiper stripbetween the claws when the wiper blade is pushed across the windshieldperpendicular to its longitudinal length.

SUMMARY OF THE INVENTION

In a prior art wiper blade of this type (DE 197 36 368.7), the wiperblade is provided with a so-called wind deflection strip in order toproduce a force component directed toward the windshield to counteractthe tendency of the wiper blade to lift off of the windshield due to theairflow at high vehicle speeds. To this end, the wind deflection striphas a leading edge during the pendulum wiping motion that is mainlyimpacted by the driving wind, said leading edge being designed as anincident surface. The cross section of the wind deflection strip hasapproximately the shape of a right triangle, one leg of which directlyopposite the support element and the hypotenuse of which represents theincident surface. This makes a sharp angle with the pendulum-like planeof motion of the wiper blade and with the surface of the windshield. Thetriangle profile used requires a relatively large amount of material tomanufacture the wind deflection strip, which is reflected in the costsof the wiper blade. Moreover, the weight of the wiper blade becomesundesirably high. Specifically, the increased mass to be accelerated inthe pendulum wiping motion requires a more powerful drive system as wellas a more expensive design of pendulum gear attached to it. Furthermore,the action of the support element and of the wiper blade can beadversely affected by the bending stiffness, which depends on itsprofile, of a wind deflection strip thus formed.

In the wiper blade according to the invention, the weight of the winddeflection strip is considerably reduced due to the cross sectionalstructure of an angular profile. Moreover, in addition to the materialsavings, there is a reduction in the moving mass along with theadvantages with respect to the design of the drive system and thependulum gear as a result. Also, the bending stiffness of the winddeflection strip is reduced, thus considerably reducing its influence onthe bending and spring behavior of the wiper blade support element. Formore detailed shapes, this wind deflection strip can be manufacturedboth as an injection molded part as well as using the simple, and thuscost effective, extrusion process.

In a further development of the invention, at least one support means isplaced between the two sides of the wind deflection strip at a distancefrom their common base point, said support means stabilizing the sides.This provides a certain degree of stiffening even when using arelatively soft material for the manufacture of the wind deflectionstrip, which provides the necessary form stability of the winddeflection strip even at a high wind loads.

What is helpful here is that the support means is made up of a wall thatextends in the longitudinal direction of the wind deflection strip thatis connected to both sides, said wall extending along the entire lengthof the wind deflection strip, if necessary.

If the support element is made up of two flexible rails, each of whichsits in a longitudinal notch associated with it, respectively, saidlongitudinal notches being open toward the opposite lateral sides of thewiper strip, and if the outer strip edges of each of said flexible railsextend out of these notches, the support means are positioned at adistance from the support element. This results in a space between thewiper strip and the support means into which the area of the wiper striplocated above the support element can extend. By correspondinglydimensioning this space, undesired friction between the wiper strip andthe wind deflection strip is prevented.

In another embodiment of the concept of the invention, the free ends ofthe sides of the wind deflection strip are provided, respectively, withclaw-like extensions that grip tightly around these exterior strip edgesof the support element at least in sections. This provides the abilityto snap the wind deflection strip onto the exterior edge or to push itonto this edge in the longitudinal direction. This makes it possible todo away with a glued connection between the wind deflection strip andthe support element. A glued connection of this type can limit theflexibility of the support element needed to attain a satisfactory wiperesult due to its stiffness.

In the process, it can be advantageous if the wind deflection strip isdesigned as a binary component whose longitudinal area provided with theclaw-like extensions is made of a harder material than the longitudinalarea lying closer to the base. In this way, the longitudinal area of thewind deflection strip provided with the extensions can be manufacturedfrom a material that is well suited for the purposes of securing thewind deflection strip to the support element, whereas the area of thewind deflection strip provided with the incident surface can be made ofa material that accounts for the further requirements on the winddeflection strip.

In a wiper blade designed in this way, it can be advantageous if thetransition from the harder longitudinal area to the softer longitudinalarea occurs near the wall.

According to another embodiment of the invention, it can be advantageousin certain applications if the wind deflection strip and the wiper stripform a one-piece component that is penetrated by a longitudinal channelin which the support element sits that is designed as a one-pieceflexible belt. It is further advantageous for the channel wall facingthe upper belt surface of the support element to constitute the supportmeans located between the two sides of the wind deflection strip.Designing the wiper blade according to the invention in this way isespecially cost-effective to install since the wind deflection strip ismade in one piece together with the wiper strip and thus someinstallation steps can be eliminated.

If the wall surfaces of the longitudinal channel facing the two beltsurfaces of the support element are provided with longitudinal ribs thatsit against the belt surfaces, this makes it considerably easier toinsert the support element into the longitudinal channel as a result ofthe reduced friction surfaces.

In a wiper blade with a one-piece component encompassing the winddeflection strip and the wiper strip, the component has threelongitudinal strip areas that are permanently connected to one anotheras seen in cross section, of which the wiper strip can be pressedagainst the windshield. The wiper strip is located on the side of thebase strip, which contains the longitudinal channel, that is oppositethe wind deflection strip. The three strip areas thus resulting must bedesigned to meet the requirements placed on them individually.

Thus, it can be very helpful if at least one of the strip areas of thecomponent is made of a material whose hardness differs from the hardnessof the other strip areas. In this way, it is possible to optimize thematerials to be used with respect to the associated tasks of theindividual strip areas.

Based on the requirements placed on the base strip, it is practical tomake it out of a harder material than the wind deflection strip. It canalso be advantageous if the transition from harder material to softermaterial occurs near the wall of the longitudinal channel that faces theupper belt surface of the support element.

In order to attain a satisfactory wipe result, it is practical to makethe wiper strip out of a softer material than the base strip.

In the process, manufacturing advantages result if the transition fromsofter material to harder material occurs near the root of the wiperstrip.

In order to avoid material such as snow, ice, etc. that is pushed awayduring the wiping process from getting jammed between the base strip andthe windshield, the base strip becomes narrower as seen in cross sectionas it approaches the wiper strip.

To fasten a connector to the wiper blade, by means of which it can beattached to a driven wiper arm, a recess is provided in the centersection of the wind deflection strip to which to attach this equipment.This recess can be produced by subsequently removing a central sectionof the wind deflection strip. However, in a wiper blade with a separatewind deflection strip, it is also conceivable to design this in twoparts as seen in the longitudinal direction, so that one half of thewind deflection strip can be attached to the support element on bothsides of the connector.

Other advantages of the further developments and configurations of theinvention are given in the following description of exemplaryembodiments illustrated in the associated drawing.

DESCRIPTION OF THE DRAWINGS

FIG. 1 a wiper blade according to the invention in a perspectiverepresentation with the wiper arm shown as a dot-dashed outline,

FIG. 2 a cross section through the wiper blade along the line II-II inFIG. 1 in an enlarged representation and

FIG. 3 the arrangement according to FIG. 2 for another embodiment of thewiper blade according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A wiper blade 10 shown in FIG. 1 has an elongated belt-shaped, flexiblespring, one or more part support element 12 that is curved in thelongitudinal direction in the un-loaded state. Located on the convexupper, or exterior, side of the belt 16 (FIGS. 1 and 2) of the supportelement facing away from the windshield 14 to be wiped there is aconnector 18 attached to the center section of the support element, forexample flat. By means of this connector, the wiper blade 10 can beremovably connected to a driven wiper arm 20 that leads to the body ofan automobile. Located on the concave lower, or inner, side of the belt22 of the curved support element 12 that directly faces the windshieldis an elongated elastic rubber wiper strip 24 that extends parallel tothe longitudinal axis of the support element 12. At the free end of thewiper arm are mating connectors, which are not illustrated in moredetail, that cooperate with the connector 18 of the wiper blade to forma hinge. The wiper arm 20, and thus the wiper blade 10, is forced in thedirection of the arrow 26 toward the windshield to be wiped whosesurface to be wiped is indicated in FIG. 1 by the dot-dashed line 14.Since the dot-dashed line indicates the greatest amount of curvature ofthe windshield surface, it can be clearly seen that the curvature of theas yet unloaded wiper blade 10, whose ends 10 sit against the windshield14, is greater than the maximum windshield curvature. The wiper bladethus has—in the unloaded state—a concave shape in comparison to thewindshield. Under pressure (arrow 26) the wiping lip 28 of the wiperblade 10 that performs the wiping presses its entire length against thewindshield surface 14 and assumes its working position approximating thestretched position. In the process, tension builds up in the belt-shapedflexible spring support element 12, ensuring proper seating of the wiperstrip 24 and its wiping lip 28 along its entire length against theautomobile windshield 14. Since the generally spherically curvedwindshield is not in fact a section of a spherical surface, the wiperblade 10 in conjunction with the wiper arm 20 must be able to constantlyadjust itself according to its respective position and to the shape ofthe windshield surface 14 during its wiping motion (double arrow 30).This necessitates a hinged connection between the wiper arm 20 and thewiper blade 10, which enables a tilting motion (double arrow 32) aboutthe hinge axis of the connection, if necessary.

Below, more detail is provided on the special configuration of the wiperblade 10 according to the invention with the help of a first embodimentof the wiper blade shown in FIG. 2.

The embodiment according to FIG. 2 of the wiper blade according to theinvention has a wiper strip 24 whose two lateral sides opposite oneanother are each provided with a longitudinal notch 34, said notchesbeing opposite one another, that is open toward the lateral side. Placedinto each of the longitudinal notches 34 is a flexible rail 36 whosewidth is larger than the depth of the longitudinal notches 34. The twoflexible rails 36 are part of the support element 12. Their outerlongitudinal edges or strip edges 38 extend out from the longitudinalnotches 34. The two flexible rails 36 are properly secured in theirlongitudinal notches 34 by end caps 40 (FIG. 1). Moreover, the connector18 (FIG. 1) can also contribute to the securing of the flexible rails 36in their longitudinal notches 34. At the side of the belt of the supportelement opposite the wiping lip 28, the wiper blade 10 is provided witha wind deflection strip 42 that is made of two pieces 41, between whichthe connector 18 for the wiper arm 20 sits on the support element 12 ina gap 65. The effective area of the wind deflection strip 42 extendsfrom each end cap 40 to the connector 18 (FIG. 1). The wind deflectionstrip 42 is made of an elastic material, for example a plastic. It hasan essentially triangular cross section with a cavity 44 that extends inthe longitudinal direction of the wind deflection strip so that—as seenin the cross section—two side 48, 50 result that diverge from a commonbase point 46 and are connected to one another at the base point. Ofthese, side 50 is provided with a sloped incident surface 54 at itsexterior that faces the main flow direction of the wind during driving(FIG. 2). The free ends of the two sides 48 and 50, which extend towardthe windshield 14, are supported at the wiper blade, i.e. at thelongitudinal edges 38 of the support element 12. To this end, they griparound the longitudinal edges 38 with tightly fitting claw-likeextensions 56, at least in sections. Thus, on one side they sit againstthe upper side of the belt 16 of the support element 12 and grip underthe lower side of the belt 22 via the extensions 56. To install the winddeflection strip 42, it is pushed onto the flexible rails 36 of thesupport element 12 in the longitudinal direction, said flexible railshaving the wiper strip 24 installed on it, so that the longitudinaledges 38 are wrapped tightly by the claw-like extensions 56 of the winddeflection strip 42. So that the wind deflection strip 42, which is madeof an elastic material, also has the necessary form stability at highrates of speed and thus at high wind pressures, a support means isplaced between the two sides 48, 50 of the wind deflection strip 42 at adistance from their common base point 46, said support means stabilizingthese sides. In the exemplary embodiment, this support means is made upof a wall 58 that is connected to the two sides 48, 50.

Furthermore, FIG. 2 shows that the wind deflection strip 42 has twolongitudinal areas 62 and 64 that are made of different materials. Thematerials have different hardnesses. In the exemplary embodiment, thelongitudinal area 64—which assumes the main tasks of the wind deflectionstrip by means of its incident surface 54—is made of a softer materialthan longitudinal area 62, which has in particular the claw-likeextensions 56 that serves to secure the wind deflection strip 42 to thesupport element 12. In the process, the transition from harderlongitudinal area 42 to the softer longitudinal area 64 occurs near thewall 58. In general, the wall 58 is placed at a distance from theclaw-like extensions 56 and the support element 12 between it and thecommon base point 46 of the two sides 48, 50, so that an recess 60results between the support element and the wall 58 that provides spacefor the strip flaps 25 of the wiper strip 24 located above the supportelement. This prevents the wiper strip 28 and the wind deflection strip42, i.e. its wall 58 from touching one another, which disrupts thewiping process. The binary wind deflection strip 42 described has aneven profile along its entire length. Thus it can be manufactured in anespecially cost-effective manner by means of the so-called complexextrusion process.

The embodiment of the wiper blade 110 according to the inventioncorresponding to FIG. 3 differs from the wiper blade according to FIG. 2especially in that the wind deflection strip 112 and the wiper strip 114are permanently connected to a base strip 130. This results in a singlestrip-shaped component 116 whose base strip area is penetrated by alongitudinal channel 118 into which a support element 120 is placed thatis designed as a one-piece flexible spring belt. This longitudinalchannel wraps around both the two belt surfaces 122 as well as the twolateral edges 123 of the support element 120. The channel walls directlyfacing the belt surfaces are provided with a number of longitudinalrecesses 124 so that longitudinal ribs 126 form between the recessesthat sit against the belt surfaces 122. This facilitates the insertionof the support element 120 into the longitudinal channel 118. At thebottom of the base strip 130 facing the windshield 114 is the wiperstrip 114 with its wiping lip 128, said wiper strip sitting against thewindshield. The base strip becomes narrower—as seen in cross section—inthe direction toward the wiper strip 114 so that walls result that slopetoward the windshield 14, which is particularly advantageous when wipingiced windshields or windshields covered with wet snow. On the upper sideof the base strip 130 that is opposite the wiper strip 114 is the winddeflection strip 112 with its incident surface 140. It also has alongitudinal cavity 142 that is placed such that between it and thelongitudinal channel 118 a wall 144 remains that connects the sides 136,138, which result from the cavity, that diverge from a common base point134 toward the windshield 14. The wall stabilizes the two side 136, 138of the wind deflection strip 112. Some of the longitudinal ribs 126 arelocated on the bottom. Further, each of the three strip areas 112, 128and 130 of the component 116 is made of a different material. This makesit possible to select the appropriate material characteristics toaccount for the different requirements placed on the respective areas.For example, the hardness values of a strip area can differ from thehardness values of the others. It is especially advantageous if the basestrip 130 is made of a harder material than the wind deflection strip112 and/or the wiper strip 114. The transition from harder material tosofter material then is intended to occur near the stabilizing wall 144or in the root 146 of the wiper strip 114 where it transitions to thebase strip 130. This results in transition regions between two directlyadjacent strip areas 112 and 130 or 130 and 114. The exact position ofthese transition regions is established on a case-by-case basis by onetrained in the art—taking into consideration the appropriate specialrequirements placed on the wiper blade.

In the embodiment of the wiper blade 110 according to FIG. 3, component116 first of all has the same length as the support element 120. Tosecure component 116 to the support element in its longitudinaldirection, it is provided at both ends with a recess so that the two endareas of the support element 120 are exposed and accessible to snap onend caps 40. Further, the wind deflection strip 112 is provided with agap or recess at its center section that in principle corresponds to thegap 65 in FIG. 1. This recess can be designed deep enough that in thisembodiment the support element 120 is exposed and thus ready for theinstallation of the connector 18. In this embodiment, it has been shownto be especially helpful if this gap 65 is attached by means of aprocess known as “water jet cutting”.

Both the wind deflection strip 42 and the wiper strip 24 as well as thecomponent 116 have an even profile along their entire length and canthus be manufactured in an especially cost-effective manner in one pieceby means of the so-called extrusion process. In the process, it is quitehelpful to manufacture these parts using the so-called complex extrusionprocess. The necessary sections can then be cut to length as needed—aswell in the embodiment according to FIG. 2.

All exemplary embodiments share the characteristic that the winddeflection strip 42 or 112 has two sides 48, 50 or 136, 138 that divergefrom a common base point 46 or 134 as seen in cross section and that areconnected to it. The free ends of the sides that face the windshield 14are supported at the wiper blade. What is also common is that theincident surface 54 or 140 is designed at the exterior of one side 50 or138 and that the profile of the cross section of the wind deflectionstrip is the same along its entire length. Further, both exemplaryembodiments have at least one support means located between the twosides 48, 50 of the wind deflection strip 42 or 112 at a distance fromtheir common base point 46 or 134. This support means is made up of awall 58 or 144 that is connected to both sides and extends in thelongitudinal direction of the wind deflection strip, said wall extendingalong the entire length of the wind deflection strip, if necessary.

1. A wiper blade for an automobile windshield, with an elongatedbelt-shaped, flexible resilient support element having a longitudinalaxis, on a lower belt surface of which that faces the windshield islocated an elastic rubber wiper strip sitting against the windshieldthat extends parallel to the longitudinal axis, and on an upper beltsurface of which a wind deflection strip is located that has an incidentsurface facing a main flow direction of a driving wind, said deflectionstrip extending in the longitudinal direction of the support element,characterized in that the wind deflection strip has two sides thatdiverge from a common base point as seen in a cross section, and thatthe incident surface is located at the exterior of one side, wherein thesupport element has outer edges, wherein the sides of the winddeflection strip have respective free ends having thereon respectiveclaw-like extensions that fittingly grip around the outer edges of thesupport element at least in sections, so that the wind deflection stripcan be snapped onto the outer edges or slid onto the outer edges in alongitudinal direction, wherein a device to connect a drive wiper arm islocated directly on the upper belt surface, the device being a unitarymember including a flat portion extending generally parallel to thesupport element and engaging the upper belt surface and a hinge portionextending generally perpendicular to and connected to the flat portion,the hinge portion being hingedly connected to an end of the drive wiperarm.
 2. A wiper blade according to claim 1, characterized in thatbetween the two sides of the wind deflection strip there is at least onesupport means located at a distance from their common base point thatstabilizes the sides.
 3. A wiper blade according to claim 2,characterized in that the support means is made up of a wall connectedto both sides that extends in the longitudinal direction of the winddeflection strip.
 4. A wiper blade according to claim 2, characterizedin that the support element includes two flexible rails each of whichsits in a longitudinal notch associated with it, respectively, saidlongitudinal notches being open toward the opposite lateral sides of thewiper strip, that the outer strip edges of each of said flexible railsextend out of these notches, and that the support means are positionedat a distance from the support element.
 5. A wiper blade according toclaim 1, characterized in that the wind deflection strip is designed asa binary component whose longitudinal area provided with the claw-likeextensions is made of a harder material than a longitudinal area lyingcloser to the base point.
 6. A wiper blade according to claim 5,characterized in that the support means is made up of a wall connectedto both sides that extends in the longitudinal direction of the winddeflection strip.
 7. A wiper blade according to claim 6, characterizedin that a transition from the harder longitudinal area to the softerlongitudinal area occurs near the wall.
 8. A wiper blade according toclaim 1, characterized in that the wind deflection strip has alongitudinal center section, and in that a recess is located in thecenter section of the wind defection strip at which to place a device toconnect a drive wiper arm.
 9. A wiper blade according to claim 1,characterized in that the wind deflection strip is made of a flexibleplastic.
 10. A wiper blade for an automobile windshield, with anelongated belt-shaped, flexible resilient support element having alongitudinal axis, on a lower belt surface of which that faces thewindshield is located an elastic rubber wiper strip sitting against thewindshield that extends parallel to the longitudinal axis, and on anupper belt surface of which a wind deflection strip is located that hasan incident surface facing a main flow direction of a driving wind, saiddeflection strip extending in the longitudinal direction of the supportelement, characterized in that the wind deflection strip has two sidesthat diverge from a common base point as seen in a cross section, thatthe incident surface is located at the exterior of one side and that theprofile of the cross section of the wind deflection strip is the samealong its entire length, wherein the support element has outer edges,wherein the sides of the wind deflection strip have respective free endshaving thereon respective claw-like extensions that fittingly griparound the outer edges of the support element at least in sections, sothat the wind deflection strip can be snapped onto the outer edges orslid onto the outer edges in a longitudinal direction, wherein a deviceto connect a drive wiper arm is located directly on the upper beltsurface, the device being a unitary member including a flat portionextending generally parallel to the support element and engaging theupper belt surface and a hinge portion extending generally perpendicularto and connected to the flat portion, the hinge portion being hingedlyconnected to an end of the drive wiper arm.
 11. A wiper blade accordingto claim 1, characterized in that between the two sides of the winddeflection strip there is at least one support means located at adistance from their common base point that stabilizes the sides.
 12. Awiper blade according to claim 11, characterized in that the supportmeans is made up of a wall connected to both sides that extends in thelongitudinal direction of the wind deflection strip.
 13. A wiper bladeaccording to claim 11, characterized in that the support elementincludes two flexible rails each of which sits in a longitudinal notchassociated with it, respectively, said longitudinal notches being opentoward the opposite lateral sides of the wiper strip, that the outerstrip edges of each of said flexible rails extend out of these notches,and that the support means are positioned at a distance from the supportelement.
 14. A wiper blade according to claim 10, characterized in thatthe wind deflection strip is designed as a binary component whoselongitudinal area provided with the claw-like extensions is made of aharder material than a longitudinal area lying closer to the base point.15. A wiper blade according to claim 14, characterized in that thesupport means is made up of a wall connected to both sides that extendsin the longitudinal direction of the wind deflection strip.
 16. A wiperblade according to claim 15, characterized in that a transition from theharder longitudinal area to the softer longitudinal area occurs near thewall.
 17. A wiper blade according to claim 10, characterized in that thewind deflection strip has a longitudinal center section, and in that arecess is located in the center section of the wind defection strip atwhich to place the device to connect a drive wiper arm.
 18. A wiperblade according to claim 10, characterized in that the wind deflectionstrip is made of a flexible plastic.